New Grow Room, help with exhaust/intake setup?

[GoneP]

last month i started work on my new grow room. most of the project is finally done. i still need to seal the room up properly, skin the outside and configure exhaust and intake, get all equipment in there etc.

the original thread here if anyone is curious on what i started with.

https://www.icmag.com/ic/showthread.php?t=331868














its nothing too impressive, just a simple room i built for flowering mainly. its dimensions are 5x8x8 (interior dimensions are smaller). actual inside is 5x7.5 and 8 feet high. ill be running a single 1000w, Magnum xxxl hood, 400cfm fan/filter over a 4x4 tray in roughly a 5x4 area (im going to make a mylar/panda film curtain to contain light in desired area) rest of area will be working space.

i would appreciate any input on how i should do intake and exhaust to best suite this setup. ill be venting to the outside via an exhaust outlet ill be cutting out near the rafters/top of the room. i planned on doing passive intakes and creating a negative pressure but am open to hear anything better. thanks in advance.

 

[Phaeton]

My room is positive pressure, intake is top and bottom vents on the same wall in a corner. Powered filtered air comes in medium velocity along the adjacent wall, splatters against the far wall and exits through passive exhausts top and bottom on the same wall as the intakes only in the other corner.
Passive intakes did not adequately stir the air in the room, supplement fans were needed along each wall blowing back towards the intakes in order to move air through the plants and lights both.
A single supplement fan is still used at the HID end of the room, the 1200 watts of CMH out heat the 2800 watts of LED and the fan is necessary to balance the room.
With a passive intake the task was near impossible and ragged leaf ends were common from tunnels of high speed air.

A single light does simplify things, but having a powered intake pushing a column of air into the room at an angle will mix the air and temperatures more than a passive intake which has the incoming air immediately stick to the closest wall to the exhaust.

I tried it both ways, it is not all that hard to reverse the fans and airflow. Don't just take my word for this.

 

[GOT_BUD?]

Imo, your exhaust should be high in the room opposite of your air intake, which should be low on the wall. Reasoning is it will help "stir" the air a bit more, and heat rises (which is why exhaust should be high on the wall). You can accomplish this with hard duct if your exhaust and intake are on the same side of the room. Just keep bends to a minimum.

Put the fan on the exhaust to create negative pressure, as well as odor control if you're using any. Oversize it if you can afford to, and use a fan speed controller to fine tune air pull into the room.

Ideally you'll also want a oscillating fan inside the room to help strengthen your plants as they grow, in addition to more "stirring" of the air. (Don't want stagnant air dead spots.)